Antiphospholipid antibodies in convalescent plasma of donors recovered from mild COVID-19 infection.

BACKGROUND AND OBJECTIVES: Passive immunization by the infusion of convalescent plasma (CP) obtained from patients who have recently recovered from COVID-19, thus having antibodies to severe acute respiratory syndrome coronavirus 2, is a potential strategy to reduce the severity of illness. A high prevalence of antiphospholipid antibodies (APLA) in patients with COVID-19 has been reported during the pandemic, raising a concern whether the use of CP could increase the risk of thrombosis in transfused patients. We aimed to evaluate the prevalence of APLA in COVID-19 CP (CCP) in order to assess the potential prothrombotic influence of transfused CCP to COVID-19 patients. MATERIALS AND METHODS: We studied the prevalence of APLA in 122 CCP samples collected from healthy donors who recovered from mild-COVID-19 at two time periods: September 2020-January 2021 (defined as 'early period' samples) and April-May 2021 (defined as 'late period' samples). Thirty-four healthy subjects unexposed to COVID-19 were used as controls. RESULTS: APLA were present in 7 of 122 (6%) CCP samples. One donor had anti-ß2-glycoprotein 1(anti-ß2GP1) IgG, one had anti-ß2GP1 IgM and five had lupus anticoagulant (LAC) using silica clotting time (SCT), all in 'late period' donors. In the control group, one subject had anti-ß2GP1 IgG, two had LAC using dilute Russell viper venom time (dRVVT) and four had LAC SCT (both LAC SCT and LAC dRVVT in one subject). CONCLUSION: The low prevalence of APLA in CCP donors reassures the safety of CCP administration to patients with severe COVID-19.

A Randomized Controlled Study Assessing Convalescent Immunoglobulins vs Convalescent Plasma for Hospitalized Patients With Coronavirus 2019.

BACKGROUND: It is unknown whether convalescent immunoglobulins (cIgGs) are better than convalescent plasma (CP) for patients with coronavirus 2019 (COVID-19). METHODS: In this randomized controlled trial, we assigned high risk COVID-19 patients with ≤10 days of symptoms, to receive cIgGs or CP. The primary endpoint was improvement on day 14 according to the World Health Organization scale. Secondary endpoints were survival on day 14, and improvement, survival, and percent of ventilated patients on day 28, and treatment response in unvaccinated and vaccinated patients. RESULTS: A total of 319 patients were included: 166 received cIgGs and 153 CP. Median age was 64 to 66 years. A total of 112 patients (67.5%) in the cIgG group and 103 patients (67.3%) in the CP group reached the primary endpoint. Difference between groups was 0.1 (95% confidence interval, -10.1 to 10.4; P = .026), failing to reach noninferiority. More patients receiving cIgG improved by day 28 (136 patients [81.9%] and 108 patients [70.6%], respectively; 95% confidence interval, 1.9-20.7; P < .001; for superiority P = .018). Seventeen patients in the cIgG group (10.2%) and 25 patients (16.3%) in the CP group required mechanical ventilation (P = .136). Sixteen (9.6%) and 23 (15%) patients, respectively, died (P = .172). More unvaccinated patients improved by day 28 in the cIgG group (84.1% vs 66.1%; P = .024), and survival was better in the cIgG group (89.9% vs 77.4%; P = .066). CONCLUSIONS: cIgGs failed to reach the primary noninferiority endpoint on day 14 but was superior to CP on day 28. Survival and improvement by day 28 in unvaccinated patients treated with cIgGs were better. In the face of new variants, cIgGs are a viable option for treating COVID-19. TRIAL REGISTRATION NUMBER: My Trials MOH_2021-01-14_009667.

Predictors of reinfection with pre-Omicron and Omicron variants of concern among individuals who recovered from COVID-19 in the first year of the pandemic.

OBJECTIVES: The predictors of SARS-CoV-2 reinfection are unclear. We examined predictors of reinfection with pre-Omicron and Omicron variants among COVID-19-recovered individuals. METHODS: Randomly selected COVID-19-recovered patients (N = 1004) who donated convalescent plasma during 2020 were interviewed between August 2021 and March 2022 regarding COVID-19 vaccination and laboratory-proven reinfection. The sera from 224 (22.3%) participants were tested for antispike (anti-S) immunoglobulin G and neutralizing antibodies. RESULTS: The participants' median age was 31.1 years (78.6% males). The overall reinfection incidence rate was 12.8%; 2.7% versus 21.6% for the pre-Omicron (mostly Delta) versus Omicron variants. Negative associations were found between fever during the first illness and pre-Omicron reinfection: relative risk 0.29 (95% confidence interval 0.09-0.94), high anti-N level at first illness and Omicron reinfection: 0.53 (0.33-0.85), and overall reinfection: 0.56 (0.37-0.84), as well as between subsequent COVID-19 vaccination with the BNT162b2 vaccine and pre-Omicron 0.15 (0.07-0.32), Omicron 0.48 (0.25-0.45), and overall reinfections 0.38 (0.25-0.58). These variables significantly correlated with immunoglobulin G anti-S follow-up levels. High pre-existing anti-S binding and neutralizing antibody levels against the SARS-CoV-2 Wuhan and Alpha strains predicted protection against Omicron reinfections. CONCLUSION: Strong immune responses after the first COVID-19 infection and subsequent vaccination with the BNT162b2 vaccine provided cross-protection against reinfections with the Delta and Omicron variants.

Predictors of mortality in COVID-19 patients treated with convalescent plasma therapy.

Several options to treat hospitalized severe COVID-19 patients have been suggested. The study aimed to describe survival in patients treated with convalescent COVID plasma (CCP) and to identify in-hospital mortality predictors. This prospective cohort study examined data from 112 severe COVID-19 patients hospitalized in the Corona Departments in an acute care hospital who received two units of CCP (at least one of them high-titer). Demographic and medical data was retrieved from the patients' electronic health records (EHR). Possible predictors for in-hospital mortality were analyzed in a univariate analysis and those found to be clinically significant were further analyzed in a multivariable analysis. Median age was 67 years (IQR 55-74) and 66 (58.9%) of them were males. Of them, 20 (17.9%) died in hospital. On multivariable analysis diabetes mellitus (p = 0.004, OR 91.54), mechanical ventilation (p = 0.001, OR 59.07) and lower albumin levels at treatment (p = 0.027, OR 0.74) were significantly associated with increased in-hospital mortality. In our study, in-hospital mortality in patients receiving CCP is similar to that reported for the general population, however certain variables mentioned above were associated with increased in-hospital mortality. In the literature, these variables were also associated with a worse outcome in patients with COVID-19 who did not receive CCP. As evidence points toward a benefit from CCP treatment in immunocompromised patients, we believe the above risk factors can further define COVID-19 patients at increased risk for mortality, enabling the selection of candidates for early treatment in an outpatient setting if possible.

Neutralization of SARS-CoV-2 Variants by rVSV-ΔG-Spike-Elicited Human Sera.

The emergence of rapidly spreading variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) poses a major challenge to the ability of vaccines and therapeutic antibodies to provide immunity. These variants contain mutations of specific amino acids that might impede vaccine efficacy. BriLife® (rVSV-ΔG-spike) is a newly developed SARS-CoV-2 vaccine candidate currently in phase II clinical trials. It is based on a replication-competent vesicular stomatitis virus (VSV) platform. The rVSV-ΔG-spike contains several spontaneously acquired spike mutations that correspond to SARS-CoV-2 variants' mutations. We show that human sera from BriLife® vaccinees preserve comparable neutralization titers towards alpha, gamma, and delta variants and show less than a three-fold reduction in the neutralization capacity of beta and omicron compared to the original virus. Taken together, we show that human sera from BriLife® vaccinees overall maintain a neutralizing antibody response against all tested variants. We suggest that BriLife®-acquired mutations may prove advantageous against future SARS-CoV-2 VOCs.

Qualifying coronavirus disease 2019 convalescent plasma donors in Israel.

BACKGROUND AND OBJECTIVES: Passive immunization using investigational COVID-19 convalescent plasma (CCP) is a promising therapeutic strategy and could improve outcome if transfused early and contain high levels of anti-SARS-CoV-2 antibodies. We report the management of a national CCP collection and distribution program in Israel. MATERIALS AND METHODS: From 1 April 2020 to 15 January 2021, 4020 volunteer donors donated 5221 CCP units and 837 (20.8%) donors donated more than once. Anti-nucleocapsid IgG antibodies were determined using chemiluminescent immunoassay method (Abbott). A statistical model based on repeated IgG tests in sequential donations was created to predict the time of antibody decline below sample/cut-off (S/CO) level of 4.0. RESULTS: Ninety-six percent of CCP donors suffered a mild disease or were asymptomatic. Older donors had higher antibody levels. Higher antibody levels (S/CO ≥4) were detected in 35.2% of the donors. Low positive (S/CO ≥1.4-3.99) were found in 37%, and 27.8% had undetectable antibodies (S/CO ≤1.4). The model predicted decrease antibody thresholds of 0.55%/day since the first CCP donation, providing guidance for the effective timing of future collections from donors with high antibody levels. CONCLUSIONS: An efficient CCP collection and distribution program was achieved, based on performing initial and repeated plasma collections, preferably from donors with higher antibody levels, and only antibody-rich units were supplied for therapeutic use. The inventory met the quantity and quality standards of the authorities, enabled to respond to the growing demand of the medical system and provide a product that may contribute to improve prognosis in patients with COVID-19.

Correlation of Anti-SARS-CoV-2 S1-specificIgG antibody levels and adverse events following vaccination with BNT162b2 mRNA COVID-19 vaccine in healthcare workers.

Currently approved anti-COVID-19 vaccines have been found to be safe and effective and almost 60% of Israeli residents are already vaccinated with BNT162b2 vaccine. This observational study was designed to evaluate the adverse events of vaccine reported by 61 healthcare workers at least 7 days after the 2nd vaccination, and to investigate the correlation of adverse events and anti-SARS-CoV-2 IgG antibody levels. The median participant's age was 51.25 years, 16 men and 45 women; 77% (44% of male and 84.5% of female participants) reported adverse events. Injection site pain, fatigue and fever were the most common symptoms, and significantly higher antibody levels (average 19,387 AU/mL) were found in participants who had fever compared to those who did not experience fever (average antibody levels of 9,977 AU/mL, p < 0.001). This finding corresponds to previous observations of higher anti-SARS-CoV-2 IgG antibody levels in COVID-19 patients presented with fever.

[COVID-19 - BLOOD GROUPS, ANTIBODIES AND CONVALESCENT PLASMA].

INTRODUCTION: Israel is currently struggling with the Coronavirus Disease (COVID-19) caused by SARS CoV-2. Transmission is increasing, with higher morbidity and mortality among populations at risk. Over-representation of blood type A was reported in COVID-19 patients with increased respiratory failure, while blood type O seems to have a protective effect. This may be caused by interference of anti-A antibodies in viral binding to the ACE receptor, different neutralization antibodies potency or variations in the stability of von Willebrand factor (VWF) multimers in different blood types. Since transfusion of convalescent COVID19 Plasma (CCP) is an accepted therapeutic modality, the Ministry of Health initiated a national project whereby CCP is collected by Magen David Adom (MDA) Blood Services using apheresis procedures and transfusions are approved by an experts committee, as part of the clinical trial or as compassionate treatment. Preliminary analysis of 49/170 patients treated so far shows improvement in 49%, with important relations with the anti-SARS-CoV-2 IgG antibodies level in the transfused plasma. Anti-SARS-CoV-2 antibodies were found in 83% of 1100 CCP donors, but a 13% decrease in antibodies level was detected in repeat donations. Blood type A was more predominant among CCP donors, when compared to MDA blood donors' data. A transfusion of CCP is a feasible and relatively safe therapeutic modality, mainly for patients with moderate COVID 19. CCP also serves as a source for the production of hyperimmune globulin for the treatment of COVID 19 and for passive immunization for populations at risk.

Compassionate use of convalescent plasma for treatment of moderate and severe pneumonia in COVID-19 patients and association with IgG antibody levels in donated plasma.

BACKGROUND: We assessed outcome of patients with moderate and severe COVID-19 following treatment with convalescent plasma (CP) and the association with IgG levels in transfused CP. METHODS: A prospective cohort study. Primary outcome was improvement at day 14 defined as alive, not on mechanical ventilation, and moderate, mild, or recovered from COVID-19. Antibody levels in CP units were unknown at the time of treatment. IgG against the spike protein S1 was subsequently measured by ELISA. Neutralizing antibodies titers were determined in a subset. Outcome was assessed in relation to the mean antibody level transfused to the patients (≤4.0 versus >4.0). FINDINGS: Of 49 patients, 11 (22.4%) had moderate, 38 (77.6%) had severe disease, 28 were ventilated. At day 14, 24 (49.0%) patients improved, 9 (18.4%) died, and 13 (26.5%) were ventilated. In 14/98 (14.3%) CP units IgG was < 1.1 (cutoff calibration) and in 60 (61.2%) ≤4.0. IgG level and neutralizing antibody titer were correlated (0.85 p < 0.001). In patients receiving ≤4.0 antibody levels, 11/30 improved (36.7%) versus 13/19 (68.4%) in patients receiving >4.0 odds ratio (OR) 0.267 [95% confidence interval (CI) 0.079-0.905], P = 0.030. In patients diagnosed >10 days prior to treatment, 4/14 (22.4%) improved in the ≤4.0 antibody group, versus 6/7 (85.7%) in the >4.0 antibody group, OR 0.048 (95% CI, 0.004-0.520), P = 0.007. No serious adverse events were reported. INTERPRETATION: Treatment with CP with higher levels of IgG against S1 may benefit patients with moderate and severe COVID-19. IgG against S1 level in CP predicts neutralization antibodies titers.

Long-term sustained response to fostamatinib in two patients with chronic refractory immune thrombocytopenia (ITP).

Care of patients with chronic immune thrombocytopenia (ITP) who are refractory to available treatments can be quite challenging. Fostamatinib, an oral Syk inhibitor, is the newest FDA-approved agent for ITP. Phase 3 clinical trials demonstrated an overall response in 43% of patients treated with fostamatinib and use for two years has been reported. Herein, we report two patients with long histories of ITP without lasting responses to numerous first-, second- and third-line therapies with prolonged responses to ongoing fostamatinib. This shows that patients unresponsive to other agents may respond to fostamatinib and can have sustained benefit.

Actin inhibition increases megakaryocyte proplatelet formation through an apoptosis-dependent mechanism.

BACKGROUND: Megakaryocytes assemble and release platelets through the extension of proplatelet processes, which are cytoplasmic extensions that extrude from the megakaryocyte and form platelets at their tips. Proplatelet formation and platelet release are complex processes that require a combination of structural rearrangements. While the signals that trigger the initiation of proplatelet formation process are not completely understood, it has been shown that inhibition of cytoskeletal signaling in mature megakaryocytes induces proplatelet formation. Megakaryocyte apoptosis may also be involved in initiation of proplatelet extension, although this is controversial. This study inquires whether the proplatelet production induced by cytoskeletal signaling inhibition is dependent on activation of apoptosis. METHODS: Megakaryocytes derived from human umbilical cord blood CD34+ cells were treated with the actin polymerization inhibitor latrunculin and their ploidy and proplatelet formation were quantitated. Apoptosis activation was analyzed by flow cytometry and luminescence assays. Caspase activity was inhibited by two compounds, ZVAD and QVD. Expression levels of pro-survival and pro-apoptosis genes were measured by quantitative RT-PCR. Protein levels of Bcl-XL, Bax and Bak were measured by western blot. Cell ultrastructure was analyzed by electron microscopy. RESULTS: Actin inhibition resulted in increased ploidy and increased proplatelet formation in cultured umbilical cord blood-derived megakaryocytes. Actin inhibition activated apoptosis in the cultured cells. The effects of actin inhibition on proplatelet formation were blocked by caspase inhibition. Increased expression of both pro-apoptotic and pro-survival genes was observed. Pro-survival protein (Bcl-xL) levels were increased compared to levels of pro-apoptotic proteins Bak and Bax. Despite apoptosis being activated, the megakaryocytes underwent minimal ultrastructural changes during actin inhibition. CONCLUSIONS: We report a correlation between increased proplatelet formation and activation of apoptosis, and that the increase in proplatelet formation in response to actin inhibition is caspase dependent. These findings support a role for apoptosis in proplatelet formation in this model.

Management of thrombocytopenia.

Thrombocytopenia is one of the most common hematologic disorders, characterized by an abnormally low number of platelets from multiple causes. The normal count of thrombocytes (platelets) is between 150,000 and 450,000 per microliter. The clinical expression of thrombocytopenia has broad variation from asymptomatic to life-threatening bleeding. Various syndromes and diseases are associated with thrombocytopenia. Thrombocytopenia is sometimes a first sign of hematologic malignancies, infectious diseases, thrombotic microangiopathies, and autoimmune disorders, and is also a common side effect of many medications. There are more than 200 diseases that include low number of platelets among their symptoms. A brief discussion of the most common etiologies and management of them is provided in this review.

Contemporary treatment of immune thrombocytopenia.

Immune thrombocytopenia is an autoimmune-mediated disorder and the treatment strategies were directed mainly to suppression of the immune system or to removal of the spleen as a place of thrombocyte destruction. In last years, it was shown that other mechanisms are responsible for development of immune thrombocytopenia: reduced thrombocyte lifespan and ineffective marrow platelet production. New treatment strategies, such as thrombopoietin receptor agonists, were developed to overcome this mechanism. Still there are a difficult minority of patients unresponsive to multiple treatments, whose have severe bleeding and another group of patients with extensive morbidity from therapy, not restricted to steroids. In this review, focused on adult patients, we discuss newer results of therapies and consider newer treatment strategies.

Identification of aldolase as a target antigen in Alzheimer's disease.

Alzheimer's disease (AD) is the most common human neurodegenerative disease, leading to progressive cognitive decline and eventually death. The prevailing paradigm on the pathogenesis of AD is that abnormally folded proteins accumulate in specific brain areas and lead to neuronal loss via apoptosis. In recent years it has become evident that an inflammatory and possibly autoimmune component exists in AD. Moreover, recent data demonstrate that immunization with amyloid-beta peptide is therapeutically effective in AD. The nature of CNS Ags that are the target of immune attack in AD is unknown. To identify potential autoantigens in AD, we tested sera IgG Abs of AD patients in immunoblots against brain and other tissue lysates. We identified a 42-kDa band in brain lysates that was detected with >50% of 45 AD sera. The band was identified by mass spectrometry to be aldolase A. Western blotting with aldolase using patient sera demonstrated a band of identical size. The Ab reactivity was verified with ELISAs using aldolase. One of 25 elderly control patients and 3 of 30 multiple sclerosis patients showed similar reactivity (p < 0.002). In enzymatic assays, anti-aldolase positive sera were found to inhibit the enzyme's activity, and the presence of the substrate (fructose 1,6-diphosphate) enhanced Ab binding. Immunization of rats and mice with aldolase in complete Freund's adjuvant was not pathogenic. These findings reveal an autoimmune component in AD, point at aldolase as a common autoantigen in this disease, and suggest a new target for potential immune modulation.